Originally Posted by Brendan

I don't mean to answer for jay but the biggest reason for time to fall off will be that with a true lsd, you can get on the throttle much sooner than with the factory vlsd. The car will also make better use of the power it is already making as it wont be spent spinning the unloaded wheel through the corner and on exit.

The factory vlsd is fine as on the street and I guess it's better than nothing, but as your grip and skill improve, it will let you down.